1. Field of the Invention
The present invention relates to an image receiving sheet and a heat transfer recording method, and in particular, to an image receiving sheet which includes an image receiving layer having high sensitivity and a heat transfer recording method using the image receiving sheet.
2. Description of the Related Art
Recently, in accordance with offices having been automated, copy machines and printers and the like which use various types of recording formats including an electrophotographic format, an ink jet format, a heat-sensitive transfer recording format and the like, have been used for various types of applications. Among such formats, the heat-sensitive transfer recording format has advantages such as easy operation, easy maintenance, compactness of the device, low costs and the like. Conventionally, two kinds of heat-sensitive transfer recording formats have been known: a heat-melting transfer format and a sublimation dye transfer format. In the heat-melting transfer format, a transfer sheet which has a melting image forming layer on a support is heated imagewise with a thermal head or a laser light to melt and transfer a melting ink to an image receiving sheet for heat-sensitive transfer recording. In the sublimation dye transfer format, a transfer sheet for heat-sensitive transfer recording, which has an image forming layer that contains a heat-diffusing dye (a sublimation dye) on a support, is used. The heat-diffusing dye is diffused and transferred to the image receiving sheet for heat-sensitive transfer recording by being heated.
In these heat-sensitive transfer formats, a heat transfer sheet is set in close contact with an image receiving sheet. Next, by heat-transfer, an ink image is formed on the image receiving sheet. Finally, the ink image is then transferred to a permanent support. In the heat transfer recording format using a conventional image receiving sheet, however, there arise problems in that transfer efficiency is insufficient when the ink image on the heat transfer sheet is heat-transferred to the image receiving sheet, and reflection density of a final image obtained by transferring the ink image on the image receiving sheet to the permanent support is insufficient.
An object of the present invention is to provide an image receiving sheet having a high transfer rate and high sensitivity, and a heat transfer recording method in which reflection density of a final image can be raised using the image receiving sheet.
In accordance with a first aspect of the present invention, there is provided an image receiving sheet comprising a support and an image layer disposed on the support, wherein the image receiving layer includes surface energy of 23 to 35 mj/m2.
In accordance with a second aspect of the present invention, there is provided an image receiving sheet comprising:
(a) a support;
(b) a first image receiving layer (a cushion layer) including a high polymer disposed on the support; and
(c) a second image receiving layer including a high polymer disposed on the first layer, and including an exterior surface comprising a surface energy of 23 to 35 mj/m2.
In accordance with a third aspect of the present invention, there is provided a method of forming an ink image, the method comprising the steps of:
(a) placing an image receiving sheet comprising a support and an image receiving layer disposed on the support, with the image receiving layer including a surface energy of 23 to 35 mj/m2, in close contact with a heat transfer sheet;
(b) forming an image on the image receiving sheet by heat transfer; and
(c) transferring the ink image to a permanent support.